Typically, a navigation device is known in which various guiding tones and warning tones are reproduced with the aim of navigating the driver. For example, car navigation includes following navigation for the driver: advance guidance about left and right turns, issuing reminders when approaching tollbooths on expressways, and issuing reminders to encourage deceleration.
However, in the conventional technology, it is difficult for the driver of the vehicle to intuitively understand the meaning of navigation.